Embedded TUF root is not up-to-date

[github-actions]

The Sigstore TUF repository contents have changed: the data embedded
in sigstore-python sources can be updated. This is not urgent but will improve cold-cache performance.

Run make update-embedded-root to update the embedded data.

This issue was filed by Check embedded root workflow run.

[woodruffw]

Assigned this to Copilot to see if it can handle it.